The present invention is directed to a method and apparatus which make it possible to complete the matching of panels to be cut in patterned fabrics. This matching process, which is carried out completely automatically, ensures that the design for each one of the panels to be cut is in its correct position. The method and apparatus can be incorporated into integral automatic fabric cutting systems in such a way as to be usable for the cutting of fabrics with patterns or designs.
The incorporation of this method and apparatus into an integrated marking and cutting system renders all the panels, cut, and with their outline clear and perfectly matched with the others making up the assembly. This makes it possible to avoid costly manual operations for matching or adjustment part by part, by the introduction of all the advantages of flexible and automatic manufacturing systems for cutting of fabrics with designs.
The method and apparatus for matching in the automatic cutting of patterned fabrics, which are the object of this invention, cannot be applied separately. To use this method, the matching apparatus must be available, and this apparatus cannot be used if the method described in these specifications is not applied.
At the present time, computerized integrated systems for the cutting of fabrics are well-known and widely used. These systems usually have a digital processor or computer, which is the central control unit of the remaining sub-systems making them up; a digitizer is used to store in the computer memory the numerical information corresponding to the geometry of the panels or patterns which are to be cut; programs and devices which make it possible to handle all the information which is contained in the computer memory and to form the distribution of the panels which are to be cut; one or more cutting machines, which are numerically controlled and which, in basic terms, consist of a table on which the fabric to be cut is spread, and a head which moves over it, driven by motors which are controlled by the central computer and which is fitted with the appropriate cutting tool (blade, laser, water jet, plasma, etc.).
These systems are described in British Patent No. 993 705 of Derek Parker, U.S. Pat. No. 3,715,945 of Takashi Mochizuki et al., or in Spanish Patent No. 489.476 of Juan Sellabona.
The use of these systems (referred to hereinafter as integrated marking and cutting systems) for the automatic cutting of fabrics has involved considerable improvements in the productivity and utilization of the material to be cut. In the case of the clothing and upholstery industry, for example, the use of such systems has considerably reduced per unit costs (garment or item of furnishing) for each unit manufactured.
However, such systems were not applicable for the cutting of patterned fabrics, e.g. checks, stripes, or a printed motif. The present invention overcomes this problem of application to fabrics with designs. Integrated marking and cutting systems were not applicable for patterned fabrics because of three main reasons:
1 The necessity for the design of the fabric to occupy a given position in the cutting of the different panels. The purpose of this is to ensure a quality finish in the end produce made up by these panels (e.g. in the case of the cutting of fabrics for the clothing industry, a garment), so that the design is continuous or symmetrical in the final product.
2 The non-rigid nature of fabrics means that it is easy for the design to be distorted. Thus, in checked or striped designs, it happens that lines are not completely straight or the size of checks is not constant; in printed patterns, the positions of the motifs are not constant, etc. These distortions make it essential to plan the exact position of the design on the fabric before it is spread. Therefore, it is not possible to distribute the panels in such a way as to ensure that, when the fabric is cut, the design will in all cases be in the correct position.
3 The difficulty created by such distortions in ensuring that, when several layers of fabric are spread superimposed for simultaneous cutting, the design is in the same position in all the layers. This makes it necessary to employ complicated spreading procedures, using needles to pierce the fabrics in order to force the design into the same position. In many cases, these types of special spreading procedures make it impossible to subsequently cut the fabrics automatically, so that it is necessary to cut them, and, as well, to make the prior distribution of the panels with manual processes.
Thus it is that, in the clothing industry, which is one of those benefiting from the invention which is the object of this patent, for the cutting of fabrics with checks, stripes or a printed pattern, it is necessary to ensure that the different panels making up a garment are matched. This is understood to mean that the design of each occupies the correct position which ensures that, in the completed garment, the design will show the continuity and symmetry which is aimed for.
The purpose of this invention is a method and apparatus which make it possible to carry out this matching process automatically. The method and apparatus may be incorporated in integrated automatic fabric cutting systems so as to make them applicable to the cutting of patterned fabrics.
With this method and apparatus, it is possible to cut patterned fabrics completely automatically, rendering the cut panels all with their outlines clean and exactly matched in each case with the others making up the group. This makes it possible to avoid costly manual panel-by-panel matching or adjustment operations, by introducing all the advantages of flexible and automatic manufacturing systems to the cutting of patterned fabrics.